Q1

When a list value appears in a Python program, it basically thinks "take out a new sheet of paper, and write some values on it."

You probably have heard of, or even met, identical twins. They look very much alike, often dress alike, and maybe even have many other things in common, but they are still two separate people with different identities. And their being separate at least opens the possibility of dressing differently if they feel like it.

Now, here is where things start getting interesting, especially to those who have prior programming experience in other languages:

y = x id(y)

Group of answer choices

a) This has the same identity as x

b) SyntaxError: multiple statements found while compiling a single statement ---- if you've gotten this answer every single time, you should probably go back to question 1 and read the directions more carefully!

c) This has a different identity from x

Q2

Many other languages introduce variables as if they name boxes to put values into (each box having a different identity) and that assigning one variable to another copies a value from one box to the other.

Python is very different in this respect. The values themselves have the identities, and variable names are just names given to those values.

Probably the best analogy is to consider that many people have different names. Someone named "William" might also be called "Will" or "Bill". "Trump", "The Donald", and "POTUS", at the time of this question are all different names for the same person. (I won't list other names people call him by)

The real world uses the word 'alias' to refer to an alternate name. Computer science also uses 'alias' (or 'aliasing') to refer to this phenomenon, which is the cause of some of the hardest bugs to find, especially in C and C++ programs.

In this case, we had a little slip of paper with 4 values on it, that was previously called 'x', and is now called 'y'. This has a surprising effect in some cases:

y.append(5) y.append(6) y.append(7) y x

Group of answer choices

a) X got changed by these operations!

b )Nothing seems to have happened

c) x and y are different from each other, because only y changes